Gun feed mechanism



26,19 5. I R... REEK' 2,3 9 8 GUN FEED MECHANI SM Filed July 9, 1941 s Sheets-Sheet 1 INVENTOR E0 YAL d. EEEK ATTORNEY June 26, 1945. I R E 2,379,185 I GUN FEED MECHANISM FilecLJuly 9, 1941 3 Sheets-Sheet 2 INVENTOR- EOYAL EEEK ATTORNEY June 26, 1945. R REEK 2,379,185

GUN .FEED MECHANISM Filed July 9, 1941 3 Sheets-Sheet 3 A52 /50 l u ATTORNE Patented June 26, 1945 GUN FEED MECHANISM Royal J. Reek, South Bend, Ind., assignorto Bendix Aviation Corporation, South Bend, Ind., a

corporation of Delaware Application July 9, 1941, Serial No. 401,574

4 Claims.

This invention relates to guns and more particularly to an ammunition feed mechanism for guns using belted ammunition and mountedfor movement, in elevation.

In rapid fire guns such as machine guns and similar automatic guns using belted ammunition, certain difiiculties arise in connection with feeding the ammunition thereto. When such guns are mounted in turrets, for example on airplanes or tanks where they must rotate in elevation, means must be provided for supplying ammunition to the guns at any point in the elevation arc. Ammunition cans cannot be secured to the guns to rotate in elevation with the guns as the load is too great even for power operated turrets, and the ammunition can will occupy too much space within the practical limits of design. Rather, the ammunition cans or containers must be stationary with respect touthe gun movement in elevation.

Ordinary ammunition containers wherein the cartridges are initially parallel to the axis of the gun have been found to be unsatisfactory. Although the cartridges feed satisfactorily when the gun is horizontal, there are design limitations in elevation as the belted ammunition forms an are from the ammunition can to the feed mechanism of the gun. The design of the pivot point of the gunfor rotationin elevation is limited bythe smallest arc in which the belted ammunition can be formed. Another type of feeding system initially places the cartridges vertically and twists them through ninety degrees to feed into the gun. In such installations the distance of the ammunition can from the gun must be no less than the distance necessary for the cartridges to twist through ninety degrees into the feeding mechanism. This system also places serious restraints on design.

I have discovered that much greater latitude of design is possible by using the hinge action of a belt of cartridges, rather-than the bending are or the twisting action. I have accordingly devised means to employ this characteristic of belts. I have discovered that by placing the cartridge initially at ninety degrees to the axis of the gun when the gun and cartridges are horizontal, and feeding the belts over a tapered roller secured to the gun, cartridges can be satisfactorily fed to the gun at any point in the elevation arc thereof. Further, my invention is characterized by simplicity of design and extremel low friction.

It is therefore an objectof my invention to provide a feed mechanism for 'a gun which will feed ammunition thereto at any angle in elevation.

Another object of my invention is to provide a feed mechanism that will present belted ammunition to the feed mechanism of the gun in a position parallel to the gun,

Another object is to provide a feed mechanism having no appreciable friction.

Still another object of my invention is to provide a simple and inexpensive feed mechanism for guns.

In the drawings forming a part of my specification:

Figure 1 is an isometric view, partly in section, of a portion of the fuselage of an airplane having a gun turret mounted therein incorporatin my invention;

Figure 2 is a top view of a portion of the left gun of Figure 1 and shows the feed mechanism;

Figure 3 is a side view of a portion of the left gun of Figure 1 shown in Figure 2 and shows the feed mechanism;

Figure 4 is a side view of my invention applied to a gun used in defending the bottom of an airplane and adapted to point downwardlywhen moved in elevation; I

Figure 5 is a plan view of a modification of my invention applied to a gun;

Figure 6 is a view in elevation of the modification shown in Figure 5; and

Figure 7 is a similar'view showing the gun in elevation and showing the path of the cartridges into the gun.

The invention is shown generally in Figure 1, wherein an airplane fuselage I0 is provided with an upper turret l2. The turret includes a stationary base member [4 to which is fastened a motor I6 for rotating the turret in azimuth. The base member I4 supports a rotatable column I 8 having a flanged heading 20 supporting a spider 22. The spider 22 has an opening 24 in which a gunner may stand while operating the turret. A seat 26 is secured to the column I8 and while sitting thereon the gunner may place his feet on a rest 28, or optionally he may stand on a platform 30.

The spider 22 is provided with trunnions 3 and with a central bracket 33 which support a rotatable gun shaft 32 driven by an elevation motor 34. Secured to the ends of shaft 32 are gun arms 36, one Of which may be seen on the left hand gun. The front or right end of each gun arm 36 is secured to a recoil absorbing unit 38 which unit supports the front end of a gun 40 having a hinged cover M. The rear end of each gun 40 is supported by arm 36 by means of a transverse bolt 42 secured to the gun and sliding in a slot 44 in the rear of the arm 36 as the gun recoils upon firing. Fastened to the bottom of each gun 4B is a case ejection chute 43 which guides the shell casings as they are ejected out of the bottom of the gun. A clip chute 45 directs clips away from the gun. A canopy 46 of transparent material encases the whole turret mechanism except the barrels of the guns 40 which protrude through slots 48.

The slots 48 permit elevation of the guns 4% from horizontal to full vertical position.

The gun feed mechanism comprising my invention is also shown in Figure 1. Fixed to the top of each gun 4|] is a plate 55 to which is secured a spindle 52 which is substantially horizontal when the guns 46 are horizontal. Mounted for rotation on shaft 52 is a frusto-conical roller 54 having a rounded cylindrical portion at the large end which is toward the gun. Stationary guide plates are secured to spindle 52 at both ends of roller 54 and include an inner plate 58 and an outer plate 58. A curved stationary guide 60 is secured to plate 56 and curves around roller 54 from top to bottom and forms a pathway to the feed mechanism of the gun 40 The feed mechanisms are shown in more detail in Figures -2 and 3-. The manner of fastening plate 50 to gun 40 forms a part of my invention. The gun 40 may be any standard type machine gun, for example the present .50 calibre aircraft 7 machine gun which has the cover 4| hinged at the front by the pin 41. The plate 50- is provided with downwardly projecting apertured ears 49 at each corner. In assembling the plate to the gun 40, the pin 41 is first removed and? the plate 50' is placed over the cover 4'-I- with the holes of the front ears 49 in alignment with the hinge hole in them 40'. The pin 41 is then passed through the ear holes and the gun and fastened, holding the front end of plate 50. The rear end ofplate 50 is heldto cover 4| by set screws. 54 screwed tightly against cover 4|. By the means described my feed mechanism may be securely fastened to a standard gun without altering the gun. Nor is there any interference with the operation of the gun as the cover 4| may be lifted for inspection and repair, lifting the feed mechanism with it. 1

Referring still to Figures 2' and 3, just inside andbelow the left gun 40 is mounted on the turret 12 an ammunition can 62 which moves. with the turret in traversing but which is stationary with respect to the elevation movement of the gun 40; The can 62 retains ammunition: 64. formed into belts by clips 66 (Figure 3), which are represented by dotted lines-in Figures 4, 5, 6 and '7. It will be noted that the axis of the cartridges in cans 62 is perpendicular to the axis of gun 40. An opening 68 is provided in the can 62 through which the ammunition 64 may be withdrawn. A roller 10 is provided near the opening 68 to guide the ammunition 64 as it leaves the ammunition can.

The tapered roller 54 may be disposed at. any angle to the gun 40 which in combination with the taper of the roller will result in the front. or right hand surface element of the roller being substantially perpendicular to the axis of the gun 4!). The diameter of the roller is limited only by the smallest arc about which the ammunition may berolled. I have-found that when the shaft 52 forms an angle of approximately 65 with. the axis of the gun and is used in combination with a roller having an included angle taper of about 40, that satisfactory results are obtained, although any' other suitable combination would be equally effective.

The operation of the device of Figures 1, 2 and 3 is as follows. The belt of ammunition is manually pulled out of can- 62 through the opening 681 and passed over the roller 54" and fed into the gun 40. The gun is then charged byreciproeating its breech bolt (not shown) until the automatic feed mechanism (not shown) of the, gun

40 grasps the belt. Upon actuation of the trigger mechanism (not shown), the gun will continuously and automatically pull the belt into the gun, ejecting shell casings into chute 43 (Figure 1) and ejecting clips out clip chute 45 (Figure 1).

During automatic firing the ammunition 64 is drawn by each gun 40 out of can 62 and over roller 10 to roller 54. The end plate 58 for roller 54 keeps the ammunition 64 from slipping down hill toward the small end of roller 54. The ten- "sion on the ammunition belt causes it to tend to slip up hill as it approaches the rear or left side of roller 54 The guide 56 near the large end of roller 54 restrains any unusual slippage tendency in this up hill direction. As the belt passes over the roller 54, first the butt ends of the cartridges and-.thenthe entire belt moves out of contact with the roller 54. The belt then passes along the path defined by the guide 60 andthus into the breech of the gun; The guide 60 prevents the ammunition from jumping off the roller asmight otherwise be possible when firing is discontinued. or in violent maneuvering of the airplane ID, or when the end of a belt is being pulled at a. rapid speed around roller 54.

As the gun. 40 is elevated, the ammunition 64 will roll over a greater portion of the circumference of roller 54. However, the first contact of the ammunition belt with the roller 54 willstill be approximately on the same forward or right hand face ofv the roller where the surface issubstantially at 90 to the axis of the gun 40. Thus it is apparent that my device will 'feed freely to the gun at any point in elevation. of the gun 40.

The embodiment of the feed mechanism shown in Figure 4is applied to a gun adapted to shoot downwardly and having, for example, an elevation or. depression are from horizontal. to straight down. In this case also it is assumed that the cartridges in the ammunition canare disposed at. right angles to the axis of the gun, and that the ammunition. can moves with the gun in azimuth but not in elevation.

In the embodiment of Figure 4, a gun 40a has fastened to its bottom in any suitable manner a plate a to which is secured a spindle 52a. Mounted on spindle 52a is a roller 54a: anda stationary end plate 58a. A guide plate corresponding to plate 56 of Figures 2 and 3 is also secured to spindle 5211 but does not appear in Figure 4. A curved guide plate 60a. surrounds the rear half of the roller 54a and forms apathzfor ammunition 64a. Ammunition 64w is supported by a roller 100. having a fixed location and over. which ammunition rolls froman ammunition can 62a.

The operation of the embodiment of Figure 4 is much like that of. Figures 1, 2 and 3. When the gun 40a. fires, its automatic mechanism pulls ammunition 64a into the gun, drawingit over roller 10a to the forward or right face of roller 54a, around the roller 54a, andfinally sliding on the cylindrical part of rollerv 54a intothe gun 40a.

' As the gun 40a is depressed so; that its barrel points downwardly, the ammunition 64a will merely wrap around wheel 54a. to a greater extent thanv shown in Figure 4 becauseof the fixed position of roller 10a. Otherwise the operation at any angle of depression is the same as at horizontal elevation positions. I l

The modification of Figures 5, 6 and 7- operates to produce the same result as the other feed mechanisms, and in much. the sameway. A. gun I40. has fastened thereto a plate I50 to which is secureda spindle. I52. Spindle I52 rotatably supports a tapered roller I54 having a rounded: cy-

lindrical portion I 51 at its large end. Secured to spindle I52 are circular segment guide plates I56 and I58 at the inner and outer ends respectively of roller I54, the guide plate I56 having a cylindrical flange portion at its periphery. Integral with plate I50 is an arm II rotatably supporting a rimmed guide roller I55, having an axis substantially parallel with the gun I40. Another arm I53 integral with plate I50 rotatably supports a roller I59 having an axis substantially perpendicular to the axis of the gun I40.

In operating the modification of Figures 5, 6 and '7, belted ammunition I64 is manually pulled out of an ammunition can I52 and pulled over roller I59, around the top of roller I54 and under roller I55 into the feed mechanism of gun I40. Gun I40 is then charged several times until the belted ammunition will automatically feed into the gun I40. The gun is now ready for automatic firing.

Upon firing the gun I40 pulls ammunition I64 out of ammunition can I62, over roller I59 to the roller I54. End guide plate I 58 keeps the cartridges from sliding down hill on the roller. Upon leaving the roller I54 the forward part of the cartridges I64 roll off the cylindrical portion I51 of roller I54, and the butt ends are contacted by the guide roller I55. Rollers I54 and I55 cooperate to align the ammunition with the axis of the gun I40 so that the ammunition will feed into the gun freely. .The guide roller I55 is particularly useful in guns mounted for recoil since the rim contacts the cartridge butts and prevents the formation of a curved path due to recoil movement. Upon cessation of firing, the inertia of the moving ammunition may tend to cause it to jumpupwardly, but this tendency is restrained by the cylindrical flange on guide I 55. Also if the airplane in which the guns I40 are mounted should be maneuvering violently, the flange on guide I56 prevents the cartridge from jumping off of wheel I54. This flange also keeps the ends of the belts from slapping upwardly as they feed rapidly over wheel I54.

Figure '7 shows the operation of the modification when the gun I40 is elevated. The operation of the feed mechanism is the same as in Figures 5 and 6 where the guns are horizontal, the only difference being that the ammunition is raised to a higher point, to reach the roller I59, but thereafter does not have .to be raised as much to contact roller I54. The roller I59 insures that the ammunition will always strike the roller I54 at a given preselected point for all elevation positions.

Although I have described my invention with reference to certain embodiments thereof, I do not intend to limit it to those embodiments or limit it in any manner other than by the terms of the following claims.

I claim:

1. A gun movable in elevation 90, a mechanism for feeding a belt of ammunition into said gun when the same is in any position up to 90 between said guide roller and said second roller, I

said tapered roller having its axis disposed with respect to the axis of said gun so that the ammunition conveyed to the gun will be carried over the top and underneath the tapered roller for changing the position of said belt of,ammunition from a vertical to a horizontal position to thereby feed the ammunition to the guide roller and thence into the side of the gun.

2. A gunmovable in elevation a mechanism for feeding a belt of ammunition into said gun when the same is in any position up to 90 elevation comprising a plate mounted on said gun, a rimmed guide roller supported by the plate and having its axis substantially parallel with the gun axis, a second roller supported by the plate and having its axis perpendicular to the gun axis, a spindle supported by the plate, a tapered roller rotatably mounted on the spindle and spaced between said guide roller and said second roller,

said tapered roller having its axis disposed with respect to the axis of said gun so that the ammunition conveyed to the gun will be carried over the top and underneath the tapered roller for changing the position of said belt of ammunition from a vertical to a horizontal position to thereby feed the ammunition to the guide roller and thence into the side of the-gun, a guide member mounted adjacent one end of said tapered roller and having a cylindrical flange encompassing a portion of said roller for preventing the ammunition belt'from jumping off the roller at times.

3. A gun movable in elevation 90, a mechanism for feeding a belt of ammunition into said gunwhen the same is in any position up to 90 elevation comprising a plate mounted on said gun, a rimmed guide roller supported by the plate and having its axis substantially parallel with the gun axis, a second roller supported by the plate and having its axis perpendicular 'to the gun axis, a spindle supported by the plate, a tapered roller rotatably mounted on the spindle and spaced between said guide roller and said second roller, said tapered roller having its axis disposed with respect to the axis of said gun so that the ammunition conveyed to the gun will be carried over the top and underneath the tapered roller for changing the position of said belt of ammunition from a vertical to a horizontal position to thereby feed the ammunition to the guide roller and thence into the side of the gun, a guide plate mounted adjacent the small end of the tapered roller and arranged to hold the belt of ammunition on the roller.

4. A gun movable in elevation 90, a mechanism for feeding a belt of ammunition into said gun when the same is in any position up to 90 elevation comprising a plate mounted on said gun, a rimmed guide roller supported by the plate and having its axis substantially parallel with the gun axis, a second roller supported by the plate and having its axis perpendicular "to the gun axis, a spindle supported by the plate, a tapered roller rotatably mounted on the spindle and spaced between said guide roller and said second roller, said tapered roller having its axis disposed with respect to the axis of said gun so that the ammunition conveyed to the gun will be carried over the top and underneath the tapered roller for changing the position of said belt of ammunition from a vertical to a horizontal position to thereby feed the ammunition to the guide roller and thence into the side of the gun, a guide plate fixed to the spindle and mounted adjacent one end'of the tapered roller for holding the belt of ammunition on the 

